xref: /netbsd-src/sys/arch/atari/stand/installboot/installboot.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: installboot.c,v 1.19 2004/03/11 07:22:25 jmc Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Waldi Ravens
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by Waldi Ravens.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/sysctl.h>
36 #include <sys/ioctl.h>
37 #include <unistd.h>
38 #include <string.h>
39 #include <stdlib.h>
40 #include <stdio.h>
41 #include <paths.h>
42 #include <fcntl.h>
43 #include <errno.h>
44 #include <err.h>
45 #include <limits.h>
46 #include <nlist.h>
47 #include <kvm.h>
48 
49 #define	DKTYPENAMES
50 #define	FSTYPENAMES
51 #include <sys/disklabel.h>
52 #include <machine/ahdilabel.h>
53 
54 #include "installboot.h"
55 
56 static void	usage __P((void));
57 static void	oscheck __P((void));
58 static u_int	abcksum __P((void *));
59 static void	setNVpref __P((void));
60 static void	setIDEpar __P((u_int8_t *, size_t));
61 static void	mkahdiboot __P((struct ahdi_root *, char *,
62 						char *, daddr_t));
63 static void	mkbootblock __P((struct bootblock *, char *,
64 				char *, struct disklabel *, u_int));
65 static void	install_fd __P((char *, struct disklabel *));
66 static void	install_sd __P((char *, struct disklabel *));
67 static void	install_wd __P((char *, struct disklabel *));
68 
69 static struct bootblock	bootarea;
70 static struct ahdi_root ahdiboot;
71 static const char	mdecpath[] = PATH_MDEC;
72 static const char	stdpath[] = PATH_STD;
73 static const char	milanpath[] = PATH_MILAN;
74 static int		nowrite = 0;
75 static int		verbose = 0;
76 static int		trackpercyl = 0;
77 static int		secpertrack = 0;
78 static int		milan = 0;
79 
80 static void
81 usage ()
82 {
83 	fprintf(stderr,
84 		"usage: installboot [options] device\n"
85 		"where options are:\n"
86 		"\t-N  do not actually write anything on the disk\n"
87 		"\t-m  use Milan boot blocks\n"
88 		"\t-t  number of tracks per cylinder (IDE disk)\n"
89 		"\t-u  number of sectors per track (IDE disk)\n"
90 		"\t-v  verbose mode\n");
91 	exit(EXIT_FAILURE);
92 }
93 
94 int
95 main (argc, argv)
96 	int	argc;
97 	char	*argv[];
98 {
99 	struct disklabel dl;
100 	char		 *dn;
101 	int		 fd, c;
102 
103 	/* check OS bootversion */
104 	oscheck();
105 
106 	/* parse options */
107 	while ((c = getopt(argc, argv, "Nmt:u:v")) != -1) {
108 		switch (c) {
109 		  case 'N':
110 			nowrite = 1;
111 			break;
112 		  case 'm':
113 			milan = 1;
114 			break;
115 		  case 't':
116 			trackpercyl = atoi(optarg);
117 			break;
118 		  case 'u':
119 			secpertrack = atoi(optarg);
120 			break;
121 		  case 'v':
122 			verbose = 1;
123 			break;
124 		  default:
125 			usage();
126 		}
127 	}
128 	argv += optind;
129 	argc -= optind;
130 	if (argc != 1)
131 		usage();
132 
133 	/* get disk label */
134 	dn = alloca(sizeof(_PATH_DEV) + strlen(argv[0]) + 8);
135 	if (!strchr(argv[0], '/')) {
136 		sprintf(dn, "%sr%s%c", _PATH_DEV, argv[0], RAW_PART + 'a');
137 		fd = open(dn, O_RDONLY);
138 		if (fd < 0 && errno == ENOENT) {
139 			sprintf(dn, "%sr%s", _PATH_DEV, argv[0]);
140 			fd = open(dn, O_RDONLY);
141 		}
142 	} else {
143 		sprintf(dn, "%s", argv[0]);
144 		fd = open(dn, O_RDONLY);
145 	}
146 	if (fd < 0)
147 		err(EXIT_FAILURE, "%s", dn);
148 	if (ioctl(fd, DIOCGDINFO, &dl))
149 		err(EXIT_FAILURE, "%s: DIOCGDINFO", dn);
150 	if (close(fd))
151 		err(EXIT_FAILURE, "%s", dn);
152 
153 	switch (dl.d_type) {
154 		case DTYPE_FLOPPY:
155 			install_fd(dn, &dl);
156 			break;
157 		case DTYPE_ST506:
158 		case DTYPE_ESDI:
159 			install_wd(dn, &dl);
160 			setNVpref();
161 			break;
162 		case DTYPE_SCSI:
163 			install_sd(dn, &dl);
164 			setNVpref();
165 			break;
166 		default:
167 			errx(EXIT_FAILURE,
168 			     "%s: %s: Device type not supported.",
169 			     dn, dktypenames[dl.d_type]);
170 	}
171 
172 	return(EXIT_SUCCESS);
173 }
174 
175 static void
176 oscheck ()
177 {
178 	struct nlist	kbv[] = { { "_bootversion" },
179 				  { NULL } };
180 	kvm_t		*kd_kern;
181 	char		errbuf[_POSIX2_LINE_MAX];
182 	u_short		kvers;
183 	struct stat	sb;
184 
185 	if (stat(_PATH_UNIX, &sb) < 0) {
186 		warnx("Cannot stat %s, no bootversion check done", _PATH_UNIX);
187 		return;
188 	}
189 
190 	kd_kern = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
191 	if (kd_kern == NULL)
192 		errx(EXIT_FAILURE, "kvm_openfiles: %s", errbuf);
193 	if (kvm_nlist(kd_kern, kbv) == -1)
194 		errx(EXIT_FAILURE, "kvm_nlist: %s", kvm_geterr(kd_kern));
195 	if (kbv[0].n_value == 0)
196 		errx(EXIT_FAILURE, "%s not in namelist", kbv[0].n_name);
197 	if (kvm_read(kd_kern, kbv[0].n_value, (char *)&kvers,
198 						sizeof(kvers)) == -1)
199 		errx(EXIT_FAILURE, "kvm_read: %s", kvm_geterr(kd_kern));
200 	kvm_close(kd_kern);
201 	if (kvers != BOOTVERSION)
202 		errx(EXIT_FAILURE, "Kern bootversion: %d, expected: %d",
203 					kvers, BOOTVERSION);
204 }
205 
206 static void
207 install_fd (devnm, label)
208 	char		 *devnm;
209 	struct disklabel *label;
210 {
211 	const char	 *machpath;
212 	char		 *xxboot, *bootxx;
213 	struct partition *rootpart;
214 
215 	if (label->d_secsize != 512)
216 		errx(EXIT_FAILURE,
217 		     "%s: %u: Block size not supported.", devnm,
218 							  label->d_secsize);
219 	if (label->d_ntracks != 2)
220 		errx(EXIT_FAILURE,
221 		     "%s: Single sided floppy not supported.", devnm);
222 
223 	if (milan)
224 		machpath = milanpath;
225 	else
226 		machpath = stdpath;
227 	xxboot = alloca(strlen(mdecpath) + strlen(machpath) + 8);
228 	sprintf(xxboot, "%s%sfdboot", mdecpath, machpath);
229 	bootxx = alloca(strlen(mdecpath) + strlen(machpath) + 8);
230 	sprintf(bootxx, "%s%sbootxx", mdecpath, machpath);
231 
232 	/* first used partition (a, b or c) */		/* XXX */
233 	for (rootpart = label->d_partitions; ; ++rootpart) {
234 		if (rootpart->p_size)
235 			break;
236 	}
237 	if (rootpart != label->d_partitions) {		/* XXX */
238 		*(label->d_partitions) = *rootpart;
239 		memset(rootpart, 0, sizeof(*rootpart));
240 	}
241 	label->d_partitions->p_fstype = FS_BSDFFS;	/* XXX */
242 	label->d_npartitions = 1;
243 	label->d_checksum = 0;
244 	label->d_checksum = dkcksum(label);
245 
246 	trackpercyl = secpertrack = 0;
247 	mkbootblock(&bootarea, xxboot, bootxx, label, 0);
248 
249 	if (!nowrite) {
250 		int	fd;
251 		if ((fd = open(devnm, O_WRONLY)) < 0)
252 			err(EXIT_FAILURE, "%s", devnm);
253 		if (write(fd, &bootarea, sizeof(bootarea)) != sizeof(bootarea))
254 			err(EXIT_FAILURE, "%s", devnm);
255 		if (close(fd))
256 			err(EXIT_FAILURE, "%s", devnm);
257 		if (verbose)
258 			printf("Boot block installed on %s\n", devnm);
259 	}
260 }
261 
262 static void
263 install_sd (devnm, label)
264 	char		 *devnm;
265 	struct disklabel *label;
266 {
267 	const char	 *machpath;
268 	char		 *xxb00t, *xxboot, *bootxx;
269 	struct disklabel rawlabel;
270 	daddr_t		 bbsec;
271 	u_int		 magic;
272 
273 	if (label->d_partitions[0].p_size == 0)
274 		errx(EXIT_FAILURE, "%s: No root-filesystem.", devnm);
275 	if (label->d_partitions[0].p_fstype != FS_BSDFFS)
276 		errx(EXIT_FAILURE, "%s: %s: Illegal root-filesystem type.",
277 		     devnm, fstypenames[label->d_partitions[0].p_fstype]);
278 
279 	bbsec = readdisklabel(devnm, &rawlabel);
280 	if (bbsec == NO_BOOT_BLOCK)
281 		errx(EXIT_FAILURE, "%s: No NetBSD boot block.", devnm);
282 	if (memcmp(label, &rawlabel, sizeof(*label)))
283 		errx(EXIT_FAILURE, "%s: Invalid NetBSD boot block.", devnm);
284 
285 	if (milan)
286 		machpath = milanpath;
287 	else
288 		machpath = stdpath;
289 	if (bbsec) {
290 		xxb00t = alloca(strlen(mdecpath) + strlen(machpath) + 14);
291 		sprintf(xxb00t, "%s%ssdb00t.ahdi", mdecpath, machpath);
292 		xxboot = alloca(strlen(mdecpath) + strlen(machpath) + 14);
293 		sprintf(xxboot, "%s%sxxboot.ahdi", mdecpath, machpath);
294 		magic = AHDIMAGIC;
295 	} else {
296 		xxb00t = NULL;
297 		xxboot = alloca(strlen(mdecpath) + strlen(machpath) + 8);
298 		sprintf(xxboot, "%s%ssdboot", mdecpath, machpath);
299 		magic = NBDAMAGIC;
300 	}
301 	bootxx = alloca(strlen(mdecpath) + strlen(machpath) + 8);
302 	sprintf(bootxx, "%s%sbootxx", mdecpath, machpath);
303 
304 	trackpercyl = secpertrack = 0;
305 	if (xxb00t)
306 		mkahdiboot(&ahdiboot, xxb00t, devnm, bbsec);
307 	mkbootblock(&bootarea, xxboot, bootxx, label, magic);
308 
309 	if (!nowrite) {
310 		off_t	bbo = bbsec * AHDI_BSIZE;
311 		int	fd;
312 
313 		if ((fd = open(devnm, O_WRONLY)) < 0)
314 			err(EXIT_FAILURE, "%s", devnm);
315 		if (lseek(fd, bbo, SEEK_SET) != bbo)
316 			err(EXIT_FAILURE, "%s", devnm);
317 		if (write(fd, &bootarea, sizeof(bootarea)) != sizeof(bootarea))
318 			err(EXIT_FAILURE, "%s", devnm);
319 		if (verbose)
320 			printf("Boot block installed on %s (sector %d)\n", devnm,
321 								    bbsec);
322 		if (xxb00t) {
323 			if (lseek(fd, (off_t)0, SEEK_SET) != 0)
324 				err(EXIT_FAILURE, "%s", devnm);
325 			if (write(fd, &ahdiboot, sizeof(ahdiboot)) != sizeof(ahdiboot))
326 				err(EXIT_FAILURE, "%s", devnm);
327 			if (verbose)
328 				printf("AHDI root  installed on %s (0)\n",
329 								devnm);
330 		}
331 		if (close(fd))
332 			err(EXIT_FAILURE, "%s", devnm);
333 	}
334 }
335 
336 static void
337 install_wd (devnm, label)
338 	char		 *devnm;
339 	struct disklabel *label;
340 {
341 	const char	 *machpath;
342 	char		 *xxb00t, *xxboot, *bootxx;
343 	struct disklabel rawlabel;
344 	daddr_t		 bbsec;
345 	u_int		 magic;
346 
347 	if (label->d_partitions[0].p_size == 0)
348 		errx(EXIT_FAILURE, "%s: No root-filesystem.", devnm);
349 	if (label->d_partitions[0].p_fstype != FS_BSDFFS)
350 		errx(EXIT_FAILURE, "%s: %s: Illegal root-filesystem type.",
351 		     devnm, fstypenames[label->d_partitions[0].p_fstype]);
352 
353 	bbsec = readdisklabel(devnm, &rawlabel);
354 	if (bbsec == NO_BOOT_BLOCK)
355 		errx(EXIT_FAILURE, "%s: No NetBSD boot block.", devnm);
356 	if (memcmp(label, &rawlabel, sizeof(*label)))
357 		errx(EXIT_FAILURE, "%s: Invalid NetBSD boot block.", devnm);
358 
359 	if (milan)
360 		machpath = milanpath;
361 	else
362 		machpath = stdpath;
363 	if (bbsec) {
364 		xxb00t = alloca(strlen(mdecpath) + strlen(machpath) + 14);
365 		sprintf(xxb00t, "%s%swdb00t.ahdi", mdecpath, machpath);
366 		xxboot = alloca(strlen(mdecpath) + strlen(machpath) + 14);
367 		sprintf(xxboot, "%s%sxxboot.ahdi", mdecpath, machpath);
368 		magic = AHDIMAGIC;
369 	} else {
370 		xxb00t = NULL;
371 		xxboot = alloca(strlen(mdecpath) + strlen(machpath) + 8);
372 		sprintf(xxboot, "%s%swdboot", mdecpath, machpath);
373 		magic = NBDAMAGIC;
374 	}
375 	bootxx = alloca(strlen(mdecpath) + strlen(machpath) + 8);
376 	sprintf(bootxx, "%s%sbootxx", mdecpath, machpath);
377 
378 	if (xxb00t)
379 		mkahdiboot(&ahdiboot, xxb00t, devnm, bbsec);
380 	mkbootblock(&bootarea, xxboot, bootxx, label, magic);
381 
382 	if (!nowrite) {
383 		int	fd;
384 		off_t	bbo;
385 
386 		bbo = bbsec * AHDI_BSIZE;
387 		if ((fd = open(devnm, O_WRONLY)) < 0)
388 			err(EXIT_FAILURE, "%s", devnm);
389 		if (lseek(fd, bbo, SEEK_SET) != bbo)
390 			err(EXIT_FAILURE, "%s", devnm);
391 		if (write(fd, &bootarea, sizeof(bootarea)) != sizeof(bootarea))
392 			err(EXIT_FAILURE, "%s", devnm);
393 		if (verbose)
394 			printf("Boot block installed on %s (sector %d)\n", devnm,
395 								    bbsec);
396 		if (xxb00t) {
397 			if (lseek(fd, (off_t)0, SEEK_SET) != 0)
398 				err(EXIT_FAILURE, "%s", devnm);
399 			if (write(fd, &ahdiboot, sizeof(ahdiboot))
400 							!= sizeof(ahdiboot))
401 				err(EXIT_FAILURE, "%s", devnm);
402 			if (verbose)
403 				printf("AHDI root  installed on %s (sector 0)\n",
404 									devnm);
405 		}
406 		if (close(fd))
407 			err(EXIT_FAILURE, "%s", devnm);
408 	}
409 }
410 
411 static void
412 mkahdiboot (newroot, xxb00t, devnm, bbsec)
413 	struct ahdi_root *newroot;
414 	char		 *xxb00t,
415 			 *devnm;
416 	daddr_t		 bbsec;
417 {
418 	struct ahdi_root tmproot;
419 	struct ahdi_part *pd;
420 	int		 fd;
421 
422 	/* read prototype root-sector */
423 	if ((fd = open(xxb00t, O_RDONLY)) < 0)
424 		err(EXIT_FAILURE, "%s", xxb00t);
425 	if (read(fd, &tmproot, sizeof(tmproot)) != sizeof(tmproot))
426 		err(EXIT_FAILURE, "%s", xxb00t);
427 	if (close(fd))
428 		err(EXIT_FAILURE, "%s", xxb00t);
429 
430 	/* set tracks/cylinder and sectors/track */
431 	setIDEpar(tmproot.ar_fill, sizeof(tmproot.ar_fill));
432 
433 	/* read current root-sector */
434 	if ((fd = open(devnm, O_RDONLY)) < 0)
435 		err(EXIT_FAILURE, "%s", devnm);
436 	if (read(fd, newroot, sizeof(*newroot)) != sizeof(*newroot))
437 		err(EXIT_FAILURE, "%s", devnm);
438 	if (close(fd))
439 		err(EXIT_FAILURE, "%s", devnm);
440 
441 	/* set bootflags */
442 	for (pd = newroot->ar_parts; pd-newroot->ar_parts < AHDI_MAXRPD; ++pd) {
443 		if (pd->ap_st == bbsec) {
444 			pd->ap_flg = 0x21;	/* bootable, pref = NetBSD */
445 			goto gotit;
446 		}
447 	}
448 	errx(EXIT_FAILURE,
449 	     "%s: NetBSD boot block not on primary AHDI partition.", devnm);
450 
451 gotit:	/* copy code from prototype and set new checksum */
452 	memcpy(newroot->ar_fill, tmproot.ar_fill, sizeof(tmproot.ar_fill));
453 	newroot->ar_checksum = 0;
454 	newroot->ar_checksum = 0x1234 - abcksum(newroot);
455 
456 	if (verbose)
457 		printf("AHDI      boot loader: %s\n", xxb00t);
458 }
459 
460 static void
461 mkbootblock (bb, xxb, bxx, label, magic)
462 	struct bootblock *bb;
463 	char		 *xxb,
464 			 *bxx;
465 	u_int		 magic;
466 	struct disklabel *label;
467 {
468 	int		 fd;
469 
470 	memset(bb, 0, sizeof(*bb));
471 
472 	/* set boot block magic */
473 	bb->bb_magic = magic;
474 
475 	/* set disk pack label */
476 	BBSETLABEL(bb, label);
477 
478 	/* set second-stage boot loader */
479 	if ((fd = open(bxx, O_RDONLY)) < 0)
480 		err(EXIT_FAILURE, "%s", bxx);
481 	if (read(fd, bb->bb_bootxx, sizeof(bb->bb_bootxx))
482 					!= sizeof(bb->bb_bootxx))
483 		err(EXIT_FAILURE, "%s", bxx);
484 	if (close(fd))
485 		err(EXIT_FAILURE, "%s", bxx);
486 
487 	/* set first-stage bootloader */
488 	if ((fd = open(xxb, O_RDONLY)) < 0)
489 		err(EXIT_FAILURE, "%s", xxb);
490 	if (read(fd, bb->bb_xxboot, sizeof(bb->bb_xxboot))
491 					!= sizeof(bb->bb_xxboot))
492 		err(EXIT_FAILURE, "%s", xxb);
493 	if (close(fd))
494 		err(EXIT_FAILURE, "%s", xxb);
495 
496 	/* set tracks/cylinder and sectors/track */
497 	setIDEpar(bb->bb_xxboot, sizeof(bb->bb_xxboot));
498 
499 	/* set AHDI checksum */
500 	*((u_int16_t *)bb->bb_xxboot + 255) = 0;
501 	*((u_int16_t *)bb->bb_xxboot + 255) = 0x1234 - abcksum(bb->bb_xxboot);
502 
503 	if (verbose) {
504 		printf("Primary   boot loader: %s\n", xxb);
505 		printf("Secondary boot loader: %s\n", bxx);
506 	}
507 }
508 
509 static void
510 setIDEpar (start, size)
511 	u_int8_t	*start;
512 	size_t		size;
513 {
514 	static const u_int8_t	mark[] = { 'N', 'e', 't', 'B', 'S', 'D' };
515 
516 	if ((u_int)trackpercyl > 255)
517 		errx(EXIT_FAILURE,
518 		     "%d: Illegal tracks/cylinder value (1..255)", trackpercyl);
519 	if ((u_int)secpertrack > 255)
520 		errx(EXIT_FAILURE,
521 		     "%d: Illegal sectors/track value (1..255)", secpertrack);
522 
523 	if (trackpercyl || secpertrack) {
524 		u_int8_t *p;
525 
526 		if (!trackpercyl)
527 			errx(EXIT_FAILURE, "Need tracks/cylinder too.");
528 		if (!secpertrack)
529 			errx(EXIT_FAILURE, "Need sectors/track too.");
530 
531 		start += 2;
532 		size  -= sizeof(mark) + 2;
533 		for (p = start + size; p >= start; --p) {
534 			if (*p != *mark)
535 				continue;
536 			if (!memcmp(p, mark, sizeof(mark)))
537 				break;
538 		}
539 		if (p < start)
540 			errx(EXIT_FAILURE,
541 			     "Malformatted xxboot prototype.");
542 
543 		*--p = secpertrack;
544 		*--p = trackpercyl;
545 
546 		if (verbose) {
547 			printf("sectors/track  : %d\n", secpertrack);
548 			printf("tracks/cylinder: %d\n", trackpercyl);
549 		}
550 	}
551 }
552 
553 static void
554 setNVpref ()
555 {
556 	static const u_char	bootpref = BOOTPREF_NETBSD;
557 	static const char	nvrdev[] = PATH_NVRAM;
558 
559 	if (!nowrite) {
560 		int	fd;
561 
562 		if ((fd = open(nvrdev, O_RDWR)) < 0)
563 			err(EXIT_FAILURE, "%s", nvrdev);
564 		if (lseek(fd, (off_t)1, SEEK_SET) != 1)
565 			err(EXIT_FAILURE, "%s", nvrdev);
566 		if (write(fd, &bootpref, (size_t)1) != 1)
567 			err(EXIT_FAILURE, "%s", nvrdev);
568 		if (close(fd))
569 			err(EXIT_FAILURE, "%s", nvrdev);
570 		if (verbose)
571 			printf("Boot preference set to NetBSD.\n");
572 	}
573 }
574 
575 static u_int
576 abcksum (bs)
577 	void	*bs;
578 {
579 	u_int16_t sum  = 0,
580 		  *st  = (u_int16_t *)bs,
581 		  *end = (u_int16_t *)bs + 256;
582 
583 	while (st < end)
584 		sum += *st++;
585 	return(sum);
586 }
587